A small section of test data from the Cardiff Hydrogen Line
Survey. Very strong signals appear as black and white in this
plot; that on the left is hydrogen emission from our own galaxy,
whilst that on the right is interference from telecommunication
radio links. The much weaker signal highlighted is from the
galaxy NGC3717.

The Lovell Telescope Multi-Beam Receiver being
hoisted up to the focus box. It shows the four feed apertures
at the base of the combined cryostat. Photo: Tony Acevedo

A
new four-beam receiver, shown in left, can now be installed
on the Lovell Telescope for use in hydrogen line and pulsar
surveys. Each beam receives signals from a slightly different
region of the sky. The whole receiver can be rotated so that,
by aligning the feeds appropriately, they can observe four parallel
strips of the sky for each scan of the telescope. It is equivalent
to building three new 76-metre telescopes but at a fraction
of the cost!

The
University of Wales H-Line Survey

The multi-beam receiver is being used by astronomers at Cardiff
to carry out a very sensitive hydrogen line survey of the northern
sky. A test observation is shown left.